2024 Honda P0401: What It Means & Is It Safe to Drive?
P0401 on the 2024 Honda: Exhaust Gas Recirculation Flow Insufficient. Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.
What this code means
The EGR system is not flowing enough exhaust gas. Usually due to carbon buildup or a stuck valve.
Common causes on the 2024 Honda
- Carbon-clogged EGR valve or passages
- Faulty EGR valve
- Faulty EGR position or differential pressure sensor
Symptoms
- Check Engine Light
- Rough idle, hesitation
- Knock under acceleration
Typical fixes
- Clean or replace EGR valve
- Clean EGR passages in intake
- Replace EGR sensor if applicable
Repair cost range
For a 2024 Honda, repairs for P0401 typically fall between $150 and $600, depending on the root cause and labor rates in your area.
Known issues on Honda
P0401 on older Honda EGR-equipped engines is almost always a stuck EGR valve or clogged port. Clean the valve with carbon solvent and verify the vacuum actuator functions. Honda phased out EGR on most models post-2002—confirm your model year has EGR before diagnosing.
Most commonly affected models